1. Field of the Invention
The present invention relates to the field of orientation-adjustable suction device, and in particular to an omni-direction rotatable dual-cup suction device, of which one suction cup can be attached to a planar fixture surface and another suction cup can be used to hold for example a tablet computer to allow for easy orientation adjustment to facilitate the operation of the computer by adjusting orientation or the use of the computer in an exhibition.
2. The Related Arts
Suction devices are commonly used. Various constructions of suction device are known, including a simply-structured suction cup that is often used to hold a navigation device or a smart mobile phone, such as PDA, inside an automobile by having a rack or clamp receiving and holding the navigation device and a cup body attached inside the front windshield. Such a simply-structured suction cup often provides a suction force that, although capable of holding a small article, such as a navigation device or PDA, is insufficient to support a large article, such as a tablet computer or an iPad. This renders the conventional suction cup useless in holding a tablet computer.
Another known type of suction device is operated through depression. The depression is often of a limited stroke, making the suction force induced by the depression limited and thus potentially insufficient. Further, any air leakage that leads to loss of suction force cannot be easily identified. Thus, it often occurs that an article held by the suction device may accidently get falling, leading to undesired damage of the article. In addition, the use of such a known suction device is not easy and also adjustment of orientation is usually not possible for such a suction device. In addition, the rack or clamp provided on the suction device is not adequate for holding a tablet computer.
A regular tablet computer, such as iPad, must be positioned on a fixture top for operation of the computer due to the fact that the tablet computer lacks an outer casing or support frame. This makes the handling and carrying of the tablet computer difficult and also not suitable for exhibition. Further, a user might wish to place the tablet computer on the laps when the user is sitting in a car or even at home. This is not convenient and may cause pain and discomfort, so that the usefulness and value of the computer may be deteriorated.
The present inventor disclosed in previous patent applications a pump combined suction device, which is provided with an alarm mark and is operated through pumping operation for evacuation of air so that the vacuum suction achieved by such a device is improved. Such a device is also provided with a locking structure. However, adjustment of angular position is not possible for such a known device. Further, such a known device is not suitable for tablet computers.
Thus, it is desired to provide a novel structure of suction device that overcomes the above discussed problems.